It has long been common to secure a load on transport vehicles such as flatbed trucks, trailers or railcars with chains that are wrapped around the entire load or coupled to it. A load binder has opposing ends with hooks that are hooked into two spaced apart chain links of a pair of chains, one going to or around the load and the other being coupled to the transport vehicle. The load binder is a device that draws the hooked links toward one another to tighten the chain and may include a latch mechanism that secures the chain in the tightened condition.
An early version of such a load binder is referred to as a lever binder and is still in current use. The lever binder uses an over-center mechanism to draw the chain links together by a fixed amount. The lever is pivoted using brute force to drive the lever to an over-center position and in the process draws the chain ends together by the fixed amount. No incremental adjustments are available. Not only is the tightening effect limited to the fixed draw length, but the substantial amount of energy that is stored in the stretching of the chain by such over-center tightening can cause kickback of the operating lever that has been known to result in serious injury or even death to the user of the device.
As an alternative, a ratchet load binder has come into use. Ratchet load binders are generally known in the hauling industry to be a safer option to that of lever binders. The ratchet load binder provides continuous incremental adjustment to tighten the chains to which it is connected and likewise gradually releases the energy stored in a tightened chain and does not produce kickback. Ratchet load binders have a tubular body with left and right hand threads at the opposing ends of the tubular body and corresponding threaded shaft portions of a pair of eye bolts or hook bolts threadedly engaged in the ends of the tubular body so as to move into and out from the tubular body responsive to rotation of the tubular body relative to the pair of eye bolts or hook bolts. Rotation of the tubular body is achieved by a ratchet mechanism having a pawl connected to a ratchet handle and a ratcheting spur gear attached to the tubular body. The ratchet handle is reciprocated back and forth to turn the tubular body relative to the threaded shaft portions which draws the threaded shafts into or out from the tubular body and thereby achieves tightening or loosening of the chain connected thereto.
While the ratchet load binder is safer to use than the lever binder, it does have drawbacks, one of which is the tendency of the one eye bolt/hook bolt coupled to the longest length of chain to rotate along with the rotation of the tubular body. That rotation reduces the amount of threading or unthreading of the eye bolt or hook bolt relative to the threaded end of the tubular body and exposes the chain to torsion forces. To prevent that rotation, the uses is expected to stabilize that one eye bolt/hook bolt against rotation with one hand while operating the ratchet handle with the other. The stoppage of that rotation becomes more difficult with increasing tension applied to the chain and with eye bolts or hook bolts that have become rusted, fouled or have become damaged, as occurs under ordinary use. Since the use of one hand to prevent rotation of the one eye bolt/hook bolt is exceedingly difficult for the majority of users, users have resorted to the use of what is called “cheater bars,” which are bars or tools such as tire irons, hammers or other such tools, that are inserted into the eye bolt or an adjoining link member between the eye bolt and a hook, to act as a lever and provide sufficient mechanical advantage to be held by the user to prevent rotation. Users have also been known to wedge such cheater bars against the flatbed of the transport vehicle to stop the rotation of the eye bolt/hook bolt. Use of such tools has created its own safety issue in that they are known to have become disengaged and strike the user.
Another drawback and safety issue of the currently available ratchet load binder has to do with the length of the threaded shaft portion that is initially extended from the threaded ends of the tube by the user when initially connecting the ratchet binder to the chains that are to be drawn together. The user does not have any way to judge how far a eye bolt/hook bolt can be unscrewed before there will be an insufficient threaded engagement with the tube.
There is, therefore, a need in the art for a ratchet load binder that can safely stabilize the attachment member (typically an eye bolt or hook bolt) that is connected to the longer length of chain securing a load. There is yet a further need for a ratchet type load binder that can indicate to the user the maximum length to which the attachment member can be unscrewed from the ends of the tube. The ratchet load binder and stabilized attachment assembly structure disclosed herein fulfills those needs, providing a solution to the drawbacks associated with prior art ratchet load binders.